The present invention relates to a device for tightening bolts having a tip to be sheared, and more particularly to a bolt tightening device having an auxiliary handle withdrawably attached to its main body.
Bolt tightening devices of this type heretofore known have an inner socket 13 and an outer socket 14 at its forward end as seen in FIG. 10.
U.S. Pat. No. 2,928,302 discloses such a device for use with a bolt 70 so shaped as shown in FIG. 11 and having a tip 71 to be sheared and a nut 70 screwed on the bolt 7. The tip 71 is fitted in the inner socket 13 with the nut 70 engaged in the outer socket 14, and the sockets 13, 14 are driven to subject the bolt tip 71 to the tightening reaction of the nut 70 through the inner socket 13 and thereby shear the tip 71.
The bolt tightening device described above is complex in interior construction, composed of many parts, made sufficiently tough to withstand a great shearing force and therefore heavy. Accordingly the device has the problem that it is difficult to handle in balance by one hand gripping a handle 3 on the rear portion of its main body 1, consequently causing much fatigue to the user.
Further since the hand is used solely for gripping the handle 3, a switch 31 on the handle 3 is inconvenient to manipulate.
To solve these problems, the device is adapted for use with both hands, for example, by attaching a screw-type auxiliary handle 4 to the main body 1 as shown in FIG. 10.
However, the auxiliary handle 4 is likely to become an obstacle depending on the location of the bolt to be tightened, and the auxiliary handle 4 must then be removed, hence cumbersome. When thus removed from the device, the handle 4 must be carried about together with the main body 1. It is then bulky and likely to become lost.